‘Lion in Winter’ @ Berkshire Theatre Group, 6/29/13

STOCKBRIDGE, Mass. — The characters in “The Lion in Winter,” which opens Berkshire Theatre Group’s 85th season, deploy epigrams and emotional violence the way people in other medieval dramas swing swords and cudgels. The intrigues, treacheries and betrayals are as outsize as any in opera or Shakespeare, but it’s the conceit of James Goldman’s play, first produced in 1966, that the dialogue is contemporary even though the action takes place more than 800 years ago, in the Plantaganet court of the English king Henry II and his wife, Eleanor of Aquitaine.

After one character complains that another has a knife, Eleanor (Jayne Atkinson), tells him, “We all have knives. It’s 1183, and we’re barbarians.” Following a shattering series of revelations, she quips, “What family doesn’t have its up and downs?”

Like George and Martha in “Who’s Afraid of Virginia Woolf?” Eleanor and Henry (Treat Williams) consider manipulation and vicious, hurtful words to be parlor games, part of an evening’s entertainment. The blood in their sport is familial connection, and when they gather for Christmas with their three sons, their collective ambition, greed and vaingloriousness occasion copious bleeding.

Director Robert Moss wisely chooses to stress the humor of the play; the poster for BTG’s production even includes the words “a comedy” immediately below the title. The material and characters are serious enough that a production could easily tip into a parody of self-importance and grandiosity without the relieving levity of wit.

Moss’ handsome, funny version plays like a funny historical soap opera in which the stakes are so high — the power to rule vast swaths of Europe and be designated king to succeed 50-year-old Henry after his death — that the characters are driven a bit mad. This is often full-throttle and full-throated drama, stuffed with people cursing and denouncing and disinheriting while sweeping through stone rooms wearing layers of wool, fur and leather. (The excellent set of imposing walls, nooks and arches is by Brett J. Banakis.)

Mostly, though, the play is an opportunity to watch actors chew on juicy dialogue and ride extreme emotional swings. Atkinson handles the lines with aplomb; she’s fully alive and believable as the desperate Eleanor, who for years has essentially been a prisoner in one of Henry’s castles. Williams rages well, but his parental connection to his sons isn’t as palpable as Eleanor’s.

The offspring are a troubled trio: The youngest, John (Karl Gregory), is his father’s favorite but a teen brat; the eldest, Richard, who will become king as Richard the Lionheart (Aaron Costa Ganis), battles his father militarily and verbally; and middle son Geoffrey (Tommy Schrider) is an intellectual and schemer but not obvious king material. They make and break promises and alliances within the same scene or even a few lines, and just when you think you’ve got the shifting strategies sorted out, another angle emerges. This family plays in toxic emotional quicksand, sucking one another down as an ugly, entertaining diversion.